Abstract: |
This study presents the results from the analysis of seismic anisotropy in Los Humeros Geothermal Field, Mexico, correlating the parameters of anisotropy: polarization (è) of the fast shear-wave qs1 and time delay (dt) of the shear-waves qS1 and qS2, with the tectonic and horizontal stress state in Los Humeros Field. By correlating and studying the phenomenon of birefringence or double refraction of shear-waves, we managed to watch matches in the directions of polarization (è) and fracturing present in-situ. The analysis includes two study periods: 1997 to 2002 and 2004 to 2008, in which we identified three areas of seismic anisotropy with the same direction of stress, fracturing and/or faulting: zone with efforts in NE-SW 20⁰ direction, mainly due to regional tectonic stresses, zone E-W (NE-SW 85 °), an area with high structural complexity, mainly produced by the variation of the stress in the E-W direction, however most of the faults are inflicted in these directions, and finally the zone NW-SE 45 ⁰, produced by stress with less tectonic influence, according to the associated fractures and polarization analysis in the stations. |